Lubricant



Patented June 16, 1931 UNITED STATES MAURICE 0. EDM'ISTON, OF ST. LOUIS, MISSOURI LUBRICANT No Drawing.

. This invention relates to improvements in lubricants and method of compounding the same, and refers more particularly to a lubricating composition having for its components a mineral oil, a fatty acid or fatty acids, and a neutralizing agent, such as a caustic blended or compounded with the mineral oil, and acid with a vehicle such as substantially anhydrous glycerin, the caustic alkali or other neutralizing agent being present in an amount sufficient to completely neutralize the acids present.

It is recognized as common practice to add fixed oils, such as animal or vegetable oils, or fats to mineral oils to form a lubricating compound and also it is Well known in the art to form a soap in a lubricating compound containing fixedoils by the use of an alkali. In the compounding of the 2 present lubricant, to a mineral oil is added a fatty acid or fatty acids, and to this mix ture is combined with an alkali dissolved in a solvent. The manner of combining the fatty acid or acids, the alkali solution and the mineral oilmay be accomplished in any suitable manner; either the fatty acids combined with the alkali solution and the resultant mixture supplied to the mineral oil, or the fatty acids added to the mineral oil, and the alkali solution combined therewith. The mixture, however made, is preferably brought to a temperature sufiicient to eliminate any moisture present. Moisture or .water has theobjective tendency of separating the constituents of the compound. The neutral compound resulting from the mixture of acid and alkali remains liquid and in solution with the mineral oil as contrasted with a lubricant in which the alkali is combined in an aqueous solution and the water driven off. The latter case produces a relatively hardl soap unsoluble in the mineral oil while in the former case the soap remainsliquid. 7

The function of the glycerin is primarily as a vehicle to carry the alkali intothe mixture to neutralize the fatty acids present. The glycerin, in the amount used, also has no substantial efiect upon the viscosity of the oil. Furthermore, the glycerin is miscible Application filed March 30, 1927. Serial No. 179,716.

with all of the ingredients, and consequently will not have the effect of an aqueous solution, in bringing about separation or ro-piness in the compound.

Among the fatty acids which are adaptable to this purpose are practically all of the range of fattyacids, including butyric, caproic, caprylic, capric, linoleic, myristic, ricinoleic, palmitic, stearic, and oleic. Among the above, which are particularly adapted to this purpose, are oleic and stearic acids. The alkali materials used to neutralize the fatty acids in the combination or mixture, are potassium and sodium hydroxides, which are added to the mixture in a solvent such as glycerin.

A further. advantage of the use of glycerin as a solvent for the alkali is the fact that the cold test of the oil is not raised and remains substantially the same as the pure mineral oil used in the combination. It is a recognized fact that in the compounding of mineral oilswith vegetable or animal oils, the cold test is decidedly effected. Fixed oils, orfats, have a relatively ihi h cold test, which effect the cold test'of t e mixture when combined with mineral oil, but in thepresent mixture or compound, the use of glycerin, which has a low cold test, ofl'sets the effect of the high cold test of the fixed oils. The combining of fixed oils and mineral oils is perhaps the present practice, which is somewhat similar to the present invention. Such combinations under the effect of high temperature and in the presence of moisture decompose to form fatty acids, which are objectionable as such, due to their effect upon the metals with which they come in contact, causing pitting and corrosion. 90

Where a combination of a mineral oil and fixed oils containing fatty acids is used at high temperatures, and in the presence of steam, or moisture, objectionable soap-like deposits accumulate in the passages and me: tallic soaps and oxides of iron are produced by the corrosion of the metal, also free carhon accumulates and all ofthese objectionable ingredients, together with deposits of solid matter from the water, produce difiiculties in the effective use of such a lubricant, this impairing the eflicient operation of the machine.

The present invention provides a lubricant 5 in which the fatty acids the alkali dissolved in the glycerin, and any soap formed has the effect of retaining the mineral oil on the metal surfaces a thin fihn, preventing metal to metal contact.

straight mineraloil which would be readily washed away due to the tearing action of moisture present. The metallic oxides, carbonaceous deposor other deleterious material, held together by mineral oil and depositing and accumulating in the cylinders or in the passageways of the engine, are cleaned by the etergent effect of the neutral soap, formed in the combination of the alkali and fatty acids. This soapis kept in a fluid state by the presence of the glycerin.

While the lubricant has been explained particularly in connection with steam engine practice, it is a fact that this oombination of mineral oil, a fatty acid, or fatty acids, and an alkali material, dissolved in glycerin is applicable to air compressors, internal combustion engines, including Diesel use. The particular mixture for each practice will. vary according to the requirements, that is, in the case of air compressor work somewhat lower viscosities will be necessary with corresponding lower cold tests than in steam engine raet ce. v

As a typic example of a steam cylinder liquid lubricant, a major proportion of Mid- Continent oil of Baum gravity having a flash point of 545- F. and a fire test of 620 F., a viscosity of 150 Sa bolt seconds at 210 F., and a cold test 0 "35 combined with 'a minor compound made from'oleic acid and potas sium hydroxide in'a solution with glycerin. The compounding. of the constituents was done in the following manner: The proportions given are according to' a pint of the lubricant. To 409 c. c. ofthe mineral oil 50 was combined 45 c. c.

fatty acid and alkali dissolved in glycerin.

Of this mixture substantially nine-thirteenths was oleic acid and four-thirteenths tassium ydroxide being soluble in glycerin corporated in the glycerine by agitation and the solution then mixed with the fatty acid. Theresultin material maythen be thor- Oughly or during the of the ingredients sufficient heat is applied to drive 'off'the' water a present. mixture wasused on a 1000- K5 motive in actual road tests and found to be are neutralized with,

This is a decided advantage over the use of r its or mineral deposits from the water, dust was proportion bf a of the mixture of the glyceriniland hydroxide; the powith the mineral oil. After especially elfective in the removal of accumulated deposits referred to heretofore. The resistance of this lubricant to the action of moisture rendered-it especially economical, it being found during the road tests that considerably less oil was used than the regular oils heretofore used.

The present invention contemplates the use of fatty acids in place of fixed oils or fats, or neutral glycerides containing fatty acids. This permlts accurately controlling the neutralization of the fatty acids resent,

and does not require the presence 0 an excess of alkali to take care of the acids as they are formed.

I The invention also contemplates any method of compounding mineral oils and fatty acids with alkali dissolved in glycerin, and furthermore the use of alkali in glycerin when combined with mineral oils, and fixed oils, or fats, to neutralize the fatty acids formed by the breaking down or decomposition of the fixed oils or fats.

I claim as my invention: 7

1. A liquid lubricant comprising a substantially water-free mixture of a major proportion of mineral oil and minor tions of a fatty acid and an alkali metal hydroxide dissolved in glycerin, the hydroxide being, in sufficient amount to neutralize the acid and the resultant neutral compound being-dissolved in the mineral oil. w 2. A liquid lubricant comprising a substantially water-free mixture ofa major proportion of mineral oil and minor proportions of oleic acid and an alkali metal hy-' droxide dissolved in glycerin, the hydroxide being in suflicient amount to neutralize the acid and the resultant neutral compound being dissolved in the mineral oil.

3. A method for producing a liquid lubricant which comprises mixing with a' major proportion of mineral oil minor proportions of a fatty acid and an alkali metal hydroxide dissolved in glycerin, the hydroxide being in sufiicient amount to neutralize the acid and forming therewith a neutral comsultant mixture sufficiently to remove water.

MAURICE. O. EDMISTON.-

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